The definition of immutable is not able to be changed.
An example of immutable is something that has happened and cannot be reversed.
never changing or varying; unchangeable
Origin of immutableMiddle English from Classical Latin immutabilis: see in- and mutable
Not subject or susceptible to change.
- im·mu′ta·bil′i·ty im·mu′ta·ble·ness
- Something that cannot be changed.